Cationic and anionic PLGA-cholesterol hybrid nanoparticles as promising platforms to enhance the trypanocidal efficacy of benznidazole and drug delivery in Trypanosoma cruzi-infected cells.

Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, remains a significant global health challenge. Currently, benznidazole (BNZ) is the primary treatment in many countries. However, this drug is limited by low bioavailability, significant host toxicity, and reduced efficacy in chronic disease phase. Additionally, cases of parasite resistance to treatment and low efficacy in in chronic disease phase have been reported. In this context, nanotechnology formulations for intracellular drug delivery have emerged as a promising alternative to improve the pharmacological properties of BNZ. In this study, we developed and evaluated cationic and anionic PLGA-cholesterol hybrid nanoparticles (HNPs) as innovative drug delivery systems for BNZ. These HNPs, functionalized with polyethyleneimine, were synthesized using a composition-dependent self-assembly method, yielding stable nanosystems with tuneable physicochemical properties. Furthermore, four release kinetic models were applied and Peppas-Sahlin demonstrated the best fit. In vitro assays confirmed the biocompatibility of HNPs with cardiomyoblasts at tested concentrations and revealed significantly enhanced trypanocidal activity against intracellular amastigotes compared to free BNZ. Transmission electron microscopy and fluorescence microscopy analyses highlighted effective nanoparticle internalization, with superior performance trypanocidal observed in anionic HNPs, which can be attributed to the residence of cationic in endo/lysosomal vesicles. Taken together, our results demonstrate the successful development of HNPs, underscoring their potential as a promising platform for the intracellular delivery of therapeutic agents.